The present invention relates to flat panel matrix displays and, in particular, to a flat panel matrix display which emulates a raster scan cathode ray tube (CRT).
One of the major performance criteria of any display system is resolution, i.e., the ability of the display system to present desired data or picture content without introducing visually noticeable interference patterns or displaying media structure patterns. The advent of television intensified the invesitigation of resolution phenomena, particularly that associated with raster scanned CRTs. In TV cameras and receivers, it was found tht interactions between video bandwidth, raster structure, and picture content could cause unwanted brightness intermodulations. Should these intermodulations become observable, the resultant optical agitation might be followed by viewer visual fatigue accompanied by misinterpretation of the displayed information. When color shadow mask CRT TVs were introduced, a further reduction in resolution occurred because of the "sieve" pheonmena associated with the placement of the shadow mask between the electron beam(s) and the display surface, and because of the dispersion of the displayed picture into tri-color dots (triads) determined by the structure of the display surface. The shadow mask also introduced additional interference patterns associated with intermodulations between the mask and the modulated electron beam(s).
With recent developments of flat panel matrix display technologies, a more discerning resolution phenomena occurs where the electronic signals representing the displayed data are necessarily quantized into finitely addressable discrete picture elements, i.e., pixels. The required display data quantization necessarily mirrors the flat panel display matrix, pixel-bypixel. Since matrix pixel sizes and spacings are finitely discrete, as opposed to CRTs where analog control of the electron beam(s) allows continuous luminance gradations and analog deflection allows continuous beam(s) positioning, care must be exercised in the design of the matrix so as to preclude unwanted visible matrix structure patterns.
It is an object of the present invention to provide improved flat panel matrix displays (i.e., active matrix LCDs), which have resolution acceptable for avionic applications.